Thanks Planks @78. As a hopeless cold solver I was about to abandon this, as I would have done last week without Meursault's (un)fortunate slips of the typing finger, and did the previous week, but your mention of the sixties gave me a PDM for the title, and I'm over halfway there now. None of the thematic words in the down clues make any sense yet, but to Catkin@79, without knowing the hints I've got away with the long entries so far just squashing em up.